With the U.S. Government requiring that the use of soldered side seams in the production of food containers be gradually eliminated and initiating the use of two-piece constructed cans or welded three piece constructed cans, a "Tear Test" procedure is now required by U.S. Government Standards for testing and controlling the quality of the side seams of such cans.
The U.S. Government requires, as quality control in the manufacturing of welded side seams, that random tests be made on the side seams of cans. The government standards require a side seam test to check for weld cracks and other faults in seam construction. While visual inspection of the cans is constantly required, a more thorough inspection makes it necessary to pull the welded seam from random sampled cans. Government standards require that this test be made at least six times in each production hour or forty-eight times in each eight-hour production shift. This test is, then, performed many times each day by thousands of inspectors, mechanics and other workers in thousands of can manufacturing plants in the United States and also elsewhere in the world.
At present, an inspector uses at least two tools, and often three, in each performance of this test. One tool is used to make two initial cuts near a side seam, one on each side of the seam. The can is then placed over a mandrel and another tool is used to pull the seam from the can. This procedure substantially confines the inspector to a work bench during the test.
The "welded can" is relatively new, and theretofore the need to improve on the quality of the can apparently has overshadowed the need to improve the methods of inspecting the product. At any rate, no advancements have been made in the tools used in this particular pulling test.
An object of the present invention is to provide a single tool that can be used to conduct the entire required test, giving at least as high quality and as useful results as the heretofore-used three tools.
Another object is to provide a single tool that cuts and pulls the seam, all in one simple operation and gives results at least equal to those obtained heretofore.
Another object is to relieve the inspector from substantial confinement to a work bench, giving him more mobility by enabling the tests to be made at various locations along the production line.
Another object of the invention is to save time and effort and to enable the test to be made at more stages of manufacturing.
Another object is to enable not only inspectors, but also mechanics and others involved in can manufacturing to make better, more effective, instant, on-the-spot checks of the side seams of a welded can.
Another object is to provide a practical, more inexpensive way to improve the testing methods now used and accepted throughout the world.
Although this tool which will be used primarily in tear-testing in three-piece-constructed welded can manufacturing side seam testing and quality control, it may also be employed in or adapted to other uses.